Because I have an unusual name, I frequently get misspelled nametags at conferences. I have solved this by always keeping a Sharpie and extra card stock in my briefcase.

This is a great idea, worthy of a resourceful consultant. However, let's take your idea one step further. Name tags are meant to introduce you and your company. Why let conference organizers influence your brand and image by their tag design? If the font is too small, people can't read your name. If you have a distinctive corporate logo, it is unlikely to be on your name tag. Sometimes the conference theme on a tag will dominate the tag, as if your name was an afterthought. And then there are tags that organizers misspelled or forgot altogether.

Tip: Take matters into your own hands by bringing your own name tag. Create a tag that highlights your brand (colors and shape are in your control and it doesn't have to be a 3x2 inch rectangle), make your name font as big as you want, and attach it in a way that suits you (women aren't forced to use the standard suit lapel clip if they don't want to) and you can hone the design over time until it is perfect for you. Make up several to keep them in convenient places.